Many metal workpieces, after forming operations such as punching or machining operations, have burrs attached thereto, which burrs extend along outer edges and also around and along edges of openings which may be punched, machined or otherwise formed in the workpiece. At least the majority of these metal burrs must be removed in order to permit utilization of the workpiece, such as incorporation thereof into an apparatus. Numerous techniques including grinding, brushing, blasting and the like have been utilized to accomplish deburring of workpieces. Many of the required techniques are complex and expensive, and often require use of expensive brushing or deburring media. Further, many of the known techniques are only partially successful in removing burrs. In particular, since workpieces typically have numerous edges, such as straight and curved edges, and interior and exterior edges, running in a multitude of directions, effective removal of the burrs from all such edges by means of any singular deburring operation has been substantially impossible. Thus, often multiple or sequential deburring operations, sometimes involving different techniques, have been required. In some instances manual deburring of selected edges is required as a final finishing step.
As one proposal for deburring of metal workpieces, there has been utilized a deburring apparatus employing a large diameter brush having generally axially-oriented bristles so that the brush defines an axial end face which is moved into contact with a workpiece. In this apparatus, the brush is rotated generally about its axis, and simultaneously the workpiece is traversed under the brush, whereby contact between the workpiece and the end face of the brush is utilized to effect deburring. With this arrangement, however, the deburring is basically bi-directional since the face of the brush on the trailing side (as viewed in the direction of movement of the workpiece relative to the brush) generally moves sidewardly in one direction, and the face of the brush on the leading side moves in the opposite direction, so that selected central areas of the workpiece are brushed primarily in a sideward back-and-forth direction. Similarly, those areas of the workpiece which are located more closely adjacent the longitudinal edges of the workpiece primarily receive only uni-directional deburring, either in the direction of movement of the workpiece on one side thereof, or in the opposite direction on the other side thereof, depending upon the direction of brush rotation. Further, with this arrangement, the width of the workpiece should normally be maintained no greater than about one-half the overall brush diameter so as to ensure more intimate contact and maximum movement of the bristles relative to the workpiece. If the workpiece is of significantly greater width relative to the brush diameter, then the deburring efficiency adjacent opposite sides of the workpiece rapidly deteriorates.
In an attempt to improve upon the deburring efficiency of apparatus using contact between the workpiece and an axial end face of a deburring brush, one known deburring arrangement employs a plurality (specifically three) of face-type deburring brushes of smaller diameter, which brushes are mounted in angularly spaced relationship in a circular pattern and are carried by a carrier which is rotatable about a central axis, with the carrier and brushes being provided with a suitable drive so that the brushes rotate individually about their axes while the carrier also rotates about its axis so as to create a planetary-type motion. In this known arrangement, all of the individual brushes are individually rotated in the same direction by the planetary-type drive. While this arrangement provides an improved deburring operation since the individual planetary-type movement of each brush is more effective in removing burrs from edges of different direction or orientation, nevertheless even this arrangement provides less than optimum deburring of some workpieces since each of the planetary brushes still undergoes the same planetating movement.
Accordingly, it is an object of the present invention to provide a deburring method and apparatus which improves upon the known methods and apparatus as described above.
More specifically, the present invention relates to an improved method and apparatus for deburring which employs a plurality of individual deburring discs such as brushes disposed in a circular pattern and individually rotated in a planetary manner similar to the abovedescribed prior arrangement. In this improved method and apparatus, however, at least one of the deburring discs is individually rotated in a direction which is contrary to the rotational direction of the other discs, with all of the discs being subject to a planetary movement, whereby the overall movement created by the deburring head assembly is of a more complex nature due to the reverse rotations of different ones of the deburring discs. The planetary deburring arrangment of this invention thus provides for movement of the deburring brushes relative to a workpiece in a true multidirectional sense, namely in substantially all directions relative to the face of the workpiece which contacts the end face of the deburring discs, so as to thereby permit highly effective and efficient removal of burrs from substantially all types, shapes and orientations of workpiece edges.
Other objects and purposes of the method and apparatus according to the present invention will be apparent upon reading the following specification and inspecting the accompanying drawings.